Pierce, 39, retired from basketball after this past season. He played for the Celtics for 15 seasons before playing for the Nets (2013-14), Wizards (2014-15) and Clippers (2015-17).

Monday’s tweet was the first hint that Pierce would be signing a contract so that he could retire as a member of the Celtics — an announcement which came several minutes later.

“We’re honored that Paul has chosen to retire as a Celtic. He is among the very best Celtics – a champion on and off the court,” said Celtics governor and managing partner Wyc Grousbeck. “We congratulate Paul on a Hall of Fame career, and look forward to seeing his number raised to the rafters of TD Garden.”

In February, in his final game in Boston, Pierce drained a 3-pointer, bringing the TD Garden crowd to a state of exuberance.

Pierce ranks third in Celtics franchise history in games played, second in points scored, third in made field goals, first in 3-pointers made, seventh in rebounds, fifth in assists, fourth in blocks, and first in steals. He was named Finals MVP for his performance in the 2008 Celtics championship win over the Los Angeles Lakers.

“It’s an honor to have this opportunity to once again call myself a Boston Celtic,” Pierce said. “The organization and city took me in and made me one of their own, and I couldn’t imagine ending my career any other way. I’m a Celtic for life.”